Gov. Larry Hogan joined state Insurance Commissioner Al Redmer Jr. in downtown Towson on Tuesday to support Redmer’s campaign for Baltimore County executive, appearing with him on a tour of small businesses.

Redmer faces state Del. Pat McDonough in the June 26 Republican primary. Three Democrats also are running for county executive — county Councilwoman Vicki Almond, state Sen. Jim Brochin and Johnny Olszewski Jr., a former state delegate.

Hogan endorsed Redmer early on and has been helping him raise money. When Redmer formally announced his candidacy in September, Hogan stood with him.

Hogan has no challengers in the gubernatorial primary, but eight Democrats — including Baltimore County Executive Kevin Kamenetz — are running to replace him.

Baltimore County is a key battleground in the governor’s race. In 2014, Hogan received more votes there than he did anywhere else in the state.

McDonough launched his campaign with a breakfast at the Boulevard Diner, a retro-style diner in Dundalk where President Donald J. Trump...

“The governor won handily in Baltimore County last time around. He’s still extremely popular in the county,” Redmer campaign spokesman Hannah Marr said. “Al’s the only candidate in the race that’s been endorsed by the governor, so having him there definitely shows people that we have his support… and that they’ll work closely together and have a strong, productive relationship.”

Redmer is one of few candidates statewide whom Hogan is actively supporting.

“He’s a longtime friend and accomplished businessman and public servant,” Hogan campaign spokesman Scott Sloofman said of Redmer. “And he’s the candidate who can win in November.”

Meanwhile, McDonough said Tuesday he supports Hogan and that the governor “will be on all my [campaign] literature.”

“Larry makes mistakes, and Redmer is one of them,” McDonough said. “I think the people of Baltimore County want to pick their executive. They don’t want the governor to pick their executive.”